A tilting pad journal bearing that can suppress unstable vibrations such as oil whip or oil whirl often used in a rotary machine where a rotary shaft rotates at high speed. The tilting pad journal bearing is a bearing which supports a rotary shaft by plural pads arranged around the rotary shaft so that the rotary shaft is rotatable. The tilting pad journal bearing is a kind of slide bearings, each of which supports the rotary shaft via an oil film of a lubricant existing between the rotary shaft and the pads. In such a tilting pad journal bearing, if the temperature of an opposite surface of each of the pads opposite the rotary shaft increases, the pad is burned out and therefore the tilting pad journal bearing may not appropriately function as a bearing.
Accordingly, technological developments have been promoted to suppress an increase of temperature of an opposite surface of a pad. For example, in Patent Document 1, the fact that the temperature of an opposite surface of a pad increases downstream in a rotation direction of a rotary shaft is focused on, and the pad configured so as to suppress an increase of temperature in a portion of the opposite surface, which is located at a downstream end in the rotation direction is disclosed. Specifically, an oil supply groove is provided in a portion (at a rear end portion) of the opposite surface (a sliding surface) of the pad, which is located at the downstream end in the rotation direction; therefore, the increase of temperature of the opposite surface can be suppressed by a lower-temperature lubricant supplied from the oil supply groove.